CHICAGO: US corn futures plunged on Tuesday after the US Department of Agriculture (USDA) projected supplies of the grain above market expectations in a monthly report, taking prices down from 7-1/2 year highs posted earlier in the day.

Soyabean futures retreated from a three-week top despite a tighter supply outlook by the USDA, while wheat futures turned lower even as the agency slashed its global stocks view by far more than analysts expected.

Corn led the sell-off as the USDA only minimally trimmed its US end-of-season stocks outlook and raised its export forecast by less than many traders had anticipated following record-large sales to China.

Tightening supplies of the feed grain and rising prices have prompted a shift by some livestock producers to use other feeds, including wheat.

“The surprise in the report is that the government only took (US corn) exports up 50 million bushels despite the fact that we had huge Chinese buying,” said Don Roose, president of US Commodities.

“With global wheat stocks down 9 million metric tons, the USDA is trying to say that we are going to feed more wheat globally,” Roose said.

USDA projected US corn ending stocks for the 2020/21 marketing year at 1.502 billion bushels and soyabean ending stocks at 120 million bushels, both down from January. Analysts polled by Reuters had expected corn ending stocks of 1.392 billion and soya ending stocks of 123 million.

Chicago Board of Trade March corn futures were down 9-3/4 cents at $5.54 a bushel at 12:19 p.m. CST (1819 GMT) after peaking at $5.74-1/4 before the report, the highest for a most-active contract since June 2013.

March soyabeans were up 8 cents at $13.95-3/4 a bushel after briefly trading lower on the day. CBOT March wheat was down 9-1/4 cents at $6.46-1/2 a bushel.